Lower the Detail Size value error

I have been going through the documentation and i have got to the part that allows me to Lower the Detail Size value of the Terrain it say go to (image below) and i have do idea were to find this. If any one could help, it would be great [image] http://docs.garagegames.com/torque-3d/official/content/documentation/World%20Editor/Editors/images/IncreasePrairieRepeat.jpg [/image]

this is the document i am following
http://docs.garagegames.com/torque-3d/official/content/documentation/World%20Editor/Tutorials/BuildingTerrains.html